Aerial torpedo



"EEN '05 UU W. G. WILSON AERIAL TORPEDO April 29, 1947.

2 Sheets-Sheet 2 Filed June 25, 1942.

Patented pr. 29, 1947 UNITED @sarai l.-

AERIAL TORPEDO Walter Gordon Wilson, Martyr Worthy, Winchester, England Application June 25, 1942, Serial No. 448,505 In Great Britain February 11, 1941 15 Claims. l This invention relates to an improved construction of aerial torpedoes and to improved means for its propulsion.

As will hereinafter 4appear the torpedo is con-y structed as, or combined with a heat engine, and is propelled after the manner of a rocket by the ejection of the burning gases from its tail end.

In considering propulsion by a rocket, the thrust given by the rocket is equal to MV where M is the mass of the discharge per second and V its velocity, Since the pressure in the rocket casing due to combustion of the burning material varies approximately as pc2, where p is the mass of discharge per cubic foot it is advisable to make p as small as possible to reduce the pressure, while making 'u as great as possible and so reduce the weight of the rocket casing. When a pyrotechnic mixture largely comprising gunpowder is used, it is found that unless the pressure of combustion P is high, incomplete combustion occurs and p is large; also as P is increased, the rate of combustion is increased and instability is then likely to occur.

For these reasons it is proposed according to one feature of this invention to control the combustion or its rate by only combining the combustible substances progressively as required so as to ensure that complete combustion as far as possible shall take place. Owing to the incomplete combustion previously mentioned a larger amount of pyro composition has to be carried than would be necessary if combustion were complete; furthermore all the elements which make up the pyro composition have to be carried by the rocket. According to this invention it is proposed to use air as one of the elements and to only carry the necessary fuel, such as hydrocarbon, to generate the required heat so as to form a heat engine. Thus in this way, the mass of discharge equals the mass of air taken in during the flight of the torpedo, plus the mass of fuel, i. e., hydrocarbon; and the driving force is equal to the difference between the MV of entrance and the MV of discharge. Also since gases are being dealt with the p of discharge is low and therefore a high velocity can be obtained with low pressures. To obtain the necessary rise of pressure to cause this arrangement to function as a heat engine, the well-known principle of the Venturi tube is utilised, but reversed; that is to say, with the usual Venturi tube, the tubular area is progressively diminished from the inlet end, but according to the present invention this is reversed by progressively increasing the tubular area from the inlet. By the ight of the torpedo, the air meeting its forward end enters the small end of the reversed venturi and as the area of the tube increases the velocity of the air is reduced and consequently the pressure is increased. During its inward movement, the air picks up a supply of fuel and when the mixture reaches the largest part of the tube, combustion is caused to take place when the mixture will immediately expand and owing to the reduced. u` obtain an increased velocity. The burning gases are now led towards the tail end of the torpedo from which they pass at great speed thereby propelling the torpedo. After the expansion of the gases the tubular area can be further contracted or remain constant in area depending on the ratio of expansion of the tube previously provided for and the reduction in p due to the heat generated, this contraction being arranged to balance the rise of pressure due to the previous expansion of the tube. To cause the heat engine to function, the torpedo must be given an initial start and means for this purpose are hereinafter described.

One example of an aerial torpedo constructed according to the invention will now be described.

Referring now to the accompanying drawing- Figure 1 is a diagrammatic View in plan of the torpedo.

Figure 2 is a horizontal longitudinal section of the head portion, and

Figure 3 is a similar section of one horizontal half of the tail end,

Figure 4 is a plan View of a modified fuel tank.

Figure 5 is a, plan View of a diaphragm detail.

Figure 6 is a vertical section of the diaphragm and the seating in which it is mounted.

Figure 7 is a sectional elevation of an ignition plug.

Figure 8 is a View similar to Figure 1 showing a modified arrangement of the parts.

Figure 9 is a detail plan view showing an arrangement of pressure balancing pipes connected with water and hydrocarbon tanks.

Figure 10 is a detail view of a device for igniting the booster charge.

In carrying the invention into effect the aerial torpedo comprises a tubular casing Ill of cylindrical cross section, and an inner casing Il, the head portion l2 of which protrudes from the open end of the casing l0. The inner casing which is concentric with the outer casing is of the torpedo shape shown in dotted lines in Figure 1 and its largest diameter is situated adjacent the open end of the outer casing Ill, Where the two cas- 3 ings are separated by an annular space I3. This annular space very slowly increases in area to- Wards the back end for a suitable distance and then gradually opens into a combustion charnber I4 which is formed by the progressive reduc- @tion in diameter of the inner casing II, the outer .'lxcasing still retaining its full cylindrical diameter.

l At about the part I5 the combustion chamber is at its largest size, after which the outer casing is contracted to the open tail end I6 of the torpedo.

Within the head I2 of the inner casing II there are arranged the devices for a supply of heated gases resulting from a mass of burning pyrotechnic or rocket composition I6a mixed with an atomised hydrocarbon indicated at I'I. The composition ISe is contained in a casing I3, fitted upon a central tubular air duct I9, and secured to a bulk-head 26 within the head I2. 'Ihe centre part of the bulk-head is fitted with a series or a ring of nozzles 2I adapted to direct the heated gases from the burning composition I5a into a mixing and vaporising chamber 22 formed between the bulk-head 29 and a second transverse bulk-head 23. The nozzles are preferably narrow in relation to their width and may be made adjustable. They are of the curved form shown so that the gases from the burning composition receive a whirling motion in the mixing chamber, where they meet and mix with jets I1 of hydrocarbon contained in a tank 24 mounted behind the bulk-head 23.

The pyrotechnic composition I6a forms a block having a front face of double annular form 25 and 26 rwith a central recess 2l, so as to provide a superficial area of considerable extent, and the mass is ignited by an ignition device 28 which is hereinafter described. When the burning composition is iirst ignited, the large incandescent surface aorded by the shape described will give out a large volume of hot gas which will pass out of the chamber I8 through the nozzles 2I, and cause a decrease in pressure from p1 to p2 and as combustion proceeds, the superiicial burning area of the composition will become progressively less as indicated by the contour lines 29, 30. Thus at the start of the torpedo iiight, an ample supply of the composition gas will be available, and the supply will then tend to decrease. The hydrocarbon in the tank 24 is preferably of relatively low volatile character such as parain, and the centre of the tank is tted with an atomising head 3I on a casing 32 to which the hydrocarbon in the tank is admitted by a supply pipe 33. The head 3| projects into the mixing chamber 22, where it is tted with a series of nozzles 34, that may be adjustable which point in an oblique direction so as to intersect the heated composition gases coming from the nozzles 2l To ensure the complete filling of the hydrocarbon tank, its upper portion is tted with an inlet supply pipe 34, which extends radially outwards through the casings I and I2 and through one of the distance pieces or studs 35 by which the outer casing I6 is spaced apart from the inner casing I2, the pipe being closed by a screw plug 36. Whilst the tank is being lled, air will be allowed to escape through a second and similar radial pipe 31 adapted to be closed by a screw plug 33. When the tank is nearly full, oil will commence to flow out of the air escape pipe 31, and both pipes may be then sealed by the screwed plugs.

The pressure necessary for driving the hydrocarbon out of the tank and atomising it, is obtained by leading a pipe 39 from the top of the lire composition tank I8, through the two bulkheads 20, 23, and into the upper part of the hydrocarbon tank 24. When the re composition IS/is ignited some of the pressure is thus tapped and led to the hydrocarbon tank to create the atomising pressure necessary, and to ensure that there shall be no leakage of hydrocarbon until the proper time, a small destructible diaphragm is placed across the pipe 39 where it enters the tank. Such a diaphragm, shown separately in Figures 5 and 6 may consist of a thin disc 4U of copper, aluminium, or other metal or material which has been previously weakened by intersecting saw cuts or creases 4I for example, the disc being mounted in a cage 42 with a perforated end. On the access of pressure through the pipe 39 the diaphragm will burst in the manner shown by dotted lines in Figure 6 at approximately the difference of pressure p1, p2 and expose the hydrocarbon to pressure, causing it to pass through the outlet pipe 33 to the atomising head 32. A similar diaphragm 43 and cage 44 are interposed in the outlet pipe 33, the object of the cage in both cases being to prevent any minute broken pieces of the diaphragm escaping. It may be noted that the supply pipe 33 is extended downward into the rear lower corner of the tank, because during flight the hydrocarbon will be pressed back and accumulate against the rear Wall. Thus the full supply of hydrocarbon will be utilised.

The mixing chamber 22 is thus supplied with a heated mixture of re gases and atomised hydrocarbon by which not only are the particles of 35 hydrocarbon evaporated, but the resulting gases are cooled, and in this'condition the mixture is injected into the annular space II, through an nnular booster nozzle 45, adjacent the air inlet end of the annular space. The nozzle is prefer- 40 ably continuous and formed by converging ex- `tensions 46 at one corner of the mixing chamber, the nozzle being at a slight Obliquity to the line of the annular space I3 between the outer casing I"Ill and the inner casing II of the torpedo body;

,land through which annular space a stream of air is passing as admitted through the open end N41 of the annular space and shown by the arrows fin Figure 2. The converging sides 46 of the nozzle i235 increase the velocity of the heated gases so 50,,that they become thoroughly mixed with the ntering air and drive along the annular space 3 towards the expansion chamber I 4, and also xerts an air injector action upon the air enterng the open end 4'I, so that the MV of the fuel as mixture will be added to the MV of the incoming air, thereby increasing the pressure in the combustion chamber I4.

The fuel mixture thus formed in the smallest area of the reversed Venturi tube is forced along the annular space at great velocity towards the combustion chamber, and after air intimate mixture is assured the area of such space is very slowly increased s0 that the fuel mixture gradually loses velocity but increases in pressure as the annular space widens into the combustion chamber I4. The maximum pressure of the fuel mixture and size of combustion chamber are reached at about or shortly before the part I5 and the mixture is then ignited by any suitable means such as a sparking plug not shown. To ensure full combustion of the fuel mixture, a grid 48 is stretched across the combustion zone formed by wires or strands of refractory material so as to encourage flame propagation, or the mixture may be ignited by jets of hot gas supplied through j ets 49 (one of which is shown in Figure 3) from a quantity of re composition stored in a central space 50 or elsewhere. Y

After combustion the gases are led away towards and through the open tail I6 of the torpedo, expanding and moving at a much higher velocity. As shown in Figure 3 this expansion chamber is shown as slightly contracting to increase velocity but it is not however essential to contract this end of the reversed Venturi tube, but a very much higher efficiency is obtained by doing so, the amount of contraction given depending on the degree of expansion previously used in the passage of the gases. It is therefore a question depending upon circumstances, the more contraction and expansion that is given increasing efhciency as a heat engine but reducing the drive for the maximum diameter used. The amount of contraction raises the pressure in the combustion chamber and therefore reduces the velocity of the incoming air and the best ratio of contraction that should be allowed is also governed by the rise of temperature in the combustion chamber. Owing to the high velocities that Will generally be used in such a heat engine, it is advisable to ignite the mixture at a number of points so as to obtain complete combustion as quickly as possible and before any appreciable contraction occurs. The combined action of the incoming velocity, plus the velocity gained by the booster jet 45 will exceed the velocity of the propagation of flame in the mixture, so that the mixture will not burn appreciably forward of the point of ignition.

In the example shown, the torpedo is built of light sheet material. The hollow head I2 is shown at 5I as being screwed into the end of the inner casing II; the outer casing I is held in concentric position with the inner casing by distance pieces such as 35 and held by countersunk screws or rivets; the two bulk-heads are held together by bolts 52 and the nozzle 45 may be formed by small fins 53a projecting from one of the extensions 46 t0 form seatings for the other extension. Other constructional details may be adopted however and where it is desired the head I2 may be reinforced to form an impact head so that it may penetrate into a target before complete explosion.

As will be seen in Figure 1, the torpedo shaped inner casing is tted With other bulk-heads 53, 54 to provide two chambers 55, 56, of which the former 55 is adapted to receive the explosive charge and the latter 56 will serve as a housing for the steering and control mechanism which is described and shown in the specification of my co-pending application No. 448,506, led June 25, 1942. In this connection it may be stated that the central tubular duct I9 shown in Figure 2, will serve to supply a charge of air to actuate the said steering mechanism. Figure 1 illustrates by way of example the use of a pair of elevators fitted to the tail end of the torpedo, these being each mounted as usual upon a transverse bearing 58. One of such elevators is shown on an enlarged scale in Figure 3 in order to illustrate the manner in which these elevators may be constructed. For this purpose each elevator carries an auxiliary member 59 within the outer casing IU which is in the stream of the expanding gases. In this way a more powerful elevator or rudder `is obtained Without exceeding the maximum diameter' 'of the torpedo and considerable controlling effort can be exerted by such an elevator or rudder before the torpedo has obtained maximum air velocity. In order to prevent overheating of the inner member 59 by the passing gases it is made hollow and filled with Water or other cooling medium and to prevent damage from excessive internal steam pressure, the bearing 58 is made with a tubular passage as indicated at 60 to allow the excessive pressure to escape. The passage may be normally sealed by a destructible diaphragm not shown, but which may be similar to the diaphragms 40 and 44 already described.

Referring to the modication shown in Figure 4, if it is desired to increase the action of the booster jet 45 by an increase in the rate of burning of the nre composition it may be that the quantity of hydrocarbon required will not reduce the temperature of the fire gases sufficiently. As the action of the booster jet is of much more importance at low speeds when the possible consumption of oil is at a minimum, it may be advantageous to use another tank 6I arranged alongside .the hydrocarbon tank 24 which is filled with water or any other cooling medium, th'e upper surface of which as well as the upper surface of the hydrocarbon in the tank 24 will be exposed, by pressure balancing pipes 39a, Figure 9, to the pressure of the fire gases from the composition chamber I3. The water will be driven out of the chamber 6I after a diaphragm indicated at 63 has been broken, through an outlet pipe 64 into the mixing chamber 22 and coiled around the hydrocarbon spray head 3|. The coil 65 is perforated so that the water is atomised and discharged as a ring of jets 66 which are designed to `cut across the oil jets Il and the re gases issuing from the nozzles 2I. By the use of this additional tank 6I the water or other cooling agent will reduce the temperature of the fire gases and increase their mass. The tank need contain only a small amount of liquid which will be exhausted by the time the torpedo has obtained such velocity that cooling is no longer necessary.

Any suitable means may be used to ignite the pyrotechnic composition in the chamber I8. One form of such an igniter is shown in Figure 2 in a position closely adjoining the fire composition. As shown in detail in Figure 7, the igniter comprises a short sleeve 61 containing an insulating body '68 embedded in which is an electrode 69 forming one pole of a suitable battery. Within the open end of the sleeve is clamped by nut I0 an ignition tip 'II of pyrotechnic mixture seated upon the insulator 68. A circuit coil 12 is embedded in the tip and forms a circuit from the electrode 69 to the metallic sleeve 6l forming the other pole. When the circuit is energised the coil 'I2 is heated to incandescence and thus ignites the tip, which in turn initiates the burning of the main body of fire composition I6.

Should it be found in practice, by the arrangement of parts shown in Figure 2 that too much consumable Weight is concentrated in the head of the torpedo, a redistribution of Weight may be obtained by moving the hydrocarbon tank further towards the rear after the manner shown in Figure 8. In such a case, the mixing chamber 22 and the re composition casing I8 remain as before, but the oil tank 24 (with the Water tank 6I if necessary) are carried by a bulk-head 13a towards the rear end of the torpedo. The pressure pipe 39 leading to the oil tank 24 is correspondingly extended as is also the pipe 33 by which the oil is fed to the spray head 3I in the mixing chamber. Such an arrangement may involve if necessary mounting the tank 24 and casing I8 somewhat vertically below the centre line of the torpedo in elevation.

From the foregoing it will be understood that the successful functioning of the heat engine depends upon the admission of air through the open end 4l of the annular space Il, which is brought about by the forward movement of the torpedo, and therefore follows that at starting the torpedo must be given initial movement. This may be obtained in various ways; it may be catapulted, dropped from aircraft, or where it is to be started from the ground a primary booster rocket may be combined with the torpedo. An illustration of this latter device is indicated in Figures 1 and 10 where 13 is a mass of pyrotechnic composition contained in a casing 'I4 mounted in the tail end of the torpedo. 'Ihe composition is ignited by any suitable means such as an ignition device of the form shown in Figure '7 arranged as 'shown in Figure 10, and discharges a stream of nre gas at great velocity through the contracted mouth of the casing and gives the necessary starting impulse to the torpedo.

It will of course be understood that at the same time as giving this starting impulse, the ignition device 28 in the head of the torpedo will be energised to commence the burning of the ignition tip li so that the main charge I6 of fire composition will be in full action before the booster charge 73 has become exhausted.

The explosive charge carried by the torpedo may be red in any suitable way either by impact, delayed action or otherwise. Such devices, however, do not form part of the invention and being well known will not be described.

From the foregoing description it will be understood that an aerial torpedo propelled in the manner described, and especially if it be launched from an aircraft, will be given considerably more acceleration thereby reducing error, shorteningr the duration of flight, and also minimising the errors due to wind and a moving target. The striking or impact velocity is increased and will also enable yaccurate bombing to be obtained from a low angle of attack although at long range, this being of particular advantage when in low cloud.

I claim:

1. An aerial torpedo propelled by the ejection of burning gas from its tail end comprising in combination a cylindrical casing open at its front and tail ends, an inner torpedo shaped body enclosed at its largest diameter and from thence back to the tail end, within and separated from the casing, by an annular air duct progressively enlarged towards the rear end of the casing, a combustion chamber formed towards the tail end of the cylindrical casing by the relative sizes of the casing and torpedo-shaped body and communicating with the annular air duct, a supply of inflammable heated gaseous fuel within the torpedo-shaped body, nozzles for directionally leading the gaseous fuel into, and in the same direction as, and mixing it with the stream of air passing along the annular air duct to the combustion chamber, means for igniting the mixture of gas and air in the combustion chamber and means for leading the exhaust gases away through the tail end of the cylindrical chamber, the arrangement being such that the MV of gas discharge from the tail end is increased.

2. An aerial torpedo as claimed in claim 1, in which the heated gaseous inflammable fuel comprises a mixture of the gas resulting from a mass of burning pyrotechnic composition and an atomised hydrocarbon.

3. In an aerial torpedo propelled by the ejection of burning gas from its tail end, having a cylindrical casing open at its front and tail ends, and an inner torpedo-shaped body enclosed except for its nose end within and separated from the casing by an annular concentric air duct, the combination within the torpedo-shaped body of a chamber containing a block of pyrotechnic composition, means for igniting the same, a chamber containing liquid hydrocarbon, a mixing chamber interposed between the two chambers containing the pyrotechnic composition and hydrocarbon respectively, means for discharging the burning pyrotechnic fire gases into the mixing chamber, means for atomising the hydrocarbon and leading it into the mixing chamber where the two are mixed and the hydrocarbon is vaporized and the re gases are cooled, a series of directional injector nozzles to feed the vaporised fuel at high speed from the mixing chamber into and moving in the same direction as the air passing along the annular air duct and increasing the momentum thereof, and a combustion chamber between the cylindrical casing and the torpedo-shaped body to receive the mixture of air and gas from the annular duct.

4. In an aerial torpedo as claimed in claim 3, the combination with the chamber containing liquid hydrocarbon and the means for atomising the hydrocarbon and passing it into the mixing chamber, of a water containing chamber, and a nozzle for spraying the water into the mixing chamber to cool the heated gases in such mixing chamber.

5. An aerial torpedo propelled by the ejection of burning gas from its tail end, comprising a cylindrical casing open at its front and tail ends, an inner torpedo-shaped body enclosed except for its nose end within the cylindrical chamber and separated from the casing by a progressively enlarging annular duct admitting air at its front open end at atmospheric pressure and high velocity, when the torpedo is in flight, a combustion chamber formed towards the tail end of the cylindrical casing by the difference in shape between the torpedo body and the casing and communicating with the annular air duct, a chamber within the torpedo body containing a supply of inflammable gas, injector nozzles from said chamber leading the gas from the chamber into the annular duct mixing it with and increasing the amount and speed of atmospheric air passing therethrough towards the combustion chamber, the progressive enlargement of the air duct transforming the original high velocity of the gaseous fuel into pressure in the combustion chamber, means for igniting the gaseous fuel, and an exhaust duct progressively reduced in size from the combustion chamber for leading away the exhaust gas at high speed.

6. In an aerial torpedo as claimed in claim 5, the combination therewith of additional ignition means in the enlarged end of the annular duct, comprising a series of supplementary burners, fed by pyrotechnic fire gases to promote complete combustion.

'7. In an aerial torpedo as claimed in claim 3, the combination of a pair of bulkheads spaced apart within the torpedo-shaped body and arranged transversely thereof to form the mixing chamber containing the supply of inflammable gas, the series of injector nozzles arranged at an angle in the circular wall of the mixing chamber dlbli mmm leading the gas into the surrounding annular air duct at such an angle as will cause an intimate mixture with the air in the duct and at the same time will promote high velocity of the air entering the duct and also of the ingoing fuel mixture.

8. An aerial torpedo comprising in combination a cylindrical outer casing, and an inner torpedo-shaped body enclosed except for its nose end in the cylindrical casing, a pair of bulkheads spaced apart and arranged transversely of the torpedo body to dene an intermediate mixing chamber, a casing behind one bulkhead, a block of burning pyrotechnic mixture in such casing, nozzles in the bulkhead to pass the burning pyrotechnic gases into the mixing chamber, a hydrocarbon containing tank behind the other bulkhead, and nozzles for atomising the hydrocarbon while passing into the mixing chamber, so as to intersect and mix with the heated gases from the pyrotechnic chamber and thereby Vaporise the hydrocarbon and cool the burning gases.

9. In an aerial torpedo as claimed in claim 8, the combination with the pyrotechnic casing and the hydrocarbon tank, of a pressure balancing pipe extending between the casing and the tank whereby the pressure from the heated gases in the former will force the hydrocarbon through the atomising nozzles into the intermediate mixing chamber.

10. In an aerial torpedo as claimed in claim 8, the combination of the hydrocarbon tank and the mixing chamber arranged side by side, an atomising head arranged in the wall of the mixing chamber, nozzles in such atomising head and communicating with the mixing chamber, and a tube extending from the rear lower corner of the hydrocarbon tank into the atomising head, to feed the hydrocarbon from the tank into the head.

11. In an aerial torpedo as claimed in claim 8,

the combination with the pyrotechnic casing, the

hydrocarbon containing tank, and the intermediate mixing chamber, of a pressure balancing pipe extending from the'casing to the tank, an atomising head in the wall of the mixing chamber adjacent the hydrocarbon tank, a supply tube extending from the lower rear corner of the hydrocarbon tank into the atomising head, a diaphragm extending across the pressure balancing pipe, and a diaphragm also extending across the hydrocarbon supply tube, both of which diaphragms will be fractured when subjected to the pressure of the gases resulting from the burning gases in the pyrotechnic chamber.

12. In an aerial torpedo as claimed in claim 8, the combination with the pyrotechnic casing, the hydrocarbon containing tank, a water tank, and the mixing chamber all in mutual communication, of pressure balancing pipes, extending from the pyrotechnic casing to both the hydrocarbon and water tanks, an atomising nozzle head in the wall of the mixing chamber adjacent the hydrocarbon tank, a supply tube from the latter extending into the atomising head, a perforated nozzle pipe round the atomising head, and a supply pipe from the water tank connected to the perforated nozzle pipe, whereby the pressure of the heated gas from the pyrotechnic chamber will be admitted to the hydrocarbon and water tanks, and force the hydrocarbon and water into the mixing chamber in the form of spray.

13. In an aerial torpedo as claimed in claim 3, the combination of the block of pyrotechnic composition which is of such a form that when it is first ignited it discharges a maximum volume of heated gas which progressively diminishes during the flight of the torpedo.

14. An aerial torpedo as claimed in claim 1, the combination with the open rear end of the cylindrical casing, of a booster charge of pvyrgtgchpic Qn, and means f'wtg the same owing to the gases from the bensi-Lei; 01mg@ belaadisrhareedtrom,iheionenendfihe c-a'sgf'the torpedo is initially set into motion.

1`5TIn an aerial torpedo propelled by the ejection of burning gas from its tail end, having a cylindrical casing open at its front and tail ends, and an inner torpedo-shaped body enclosed except for its nose end Within and separated from the casing by an annular concentric air duct, the combination within the torpedo-shaped body of a chamber containing a block of pyrotechnic composition, means for igniting the same, a chamber containing liquid hydrocarbon, a mixing chamber interposed between the two chambers containing the pyrotechnic composition and hydrocarbon respectively, means for discharging the burning pyrotechnic iire gases into the mixing chamber, means for atomising the hydrocarbon and leading it into the mixing chamber where the two are mixed and the hydrocarbon is vaporised and the re gases are cooled, a bulkhead extending transversely of, and being fixed to, the circumferential wall of the torpedo-shaped body, a second bulkhead spaced apart from the first to define the mixing chamber containing the mixture of iniiammable gas, lateral extensions of the wall of the mixing chamber, and of the second bulkhead where they meet at the circumference of the mixing chamber, which extensions converge to form a continuous ring nozzle to inject the mixture of inflammable gas at high velocity into the annular duct surrounding the mixing chamber at an angle appropriate to the formation of an intimate mixture.

WALTER GORDON WILSON.

REFERENCES CITED The following references are of record in the le of this patent:

FOREIGN PATENTS Number Country Date 618,668 Germany Sept. 13, 1935 516,463 Britain Jan. 2, 1940 126,325 Britain May 15, 1919 

